Endoscopes for medical use have been adopted for various diagnostic and medical treatment procedures. Endoscopes have been used for the diagnosis and treatment of a wide range of diseases and disorders that often require a physician to access the tortuous and relatively small cross-sectional areas of a patient's internal anatomical body lumens. A patient's pancreaticobiliary system (including the anatomical regions of the gall bladder, pancreas, and the biliary tree), for example, is accessed for diagnosis, and/or treatment of disorders of certain portions of the digestive system.
During treatment of the digestive system, endoscopes are often used to access and visualize a patient's pancreaticobiliary system. Once the endoscope is positioned in the desired body portion, a treatment instrument can be advanced through the working channel of the endoscope to the desired body portion. The endoscope and treatment instrument may then be manipulated as desired for visualization and treatment respectively.
Endoscopic retrograde cholangiopancreatography (ERCP) is one example of a medical procedure that uses an endoscope. ERCP can enable the physician to diagnose problems in the liver, gallbladder, bile ducts, and pancreas. The liver is a large organ that, among other things, makes a liquid called bile that helps with digestion. The gallbladder is a small, pear-shaped organ that stores bile until it is needed for digestion. The bile ducts are tubes that carry bile from the liver to the gallbladder and small intestine. These ducts are sometimes called the biliary tree. The pancreas is a large gland that produces chemicals that help with digestion and hormones such as insulin.
The biliary system delivers bile produced by the liver to the duodenum where the bile assists other gastric fluids in digesting food. The biliary system includes the liver, as well as a plurality of bodily channels and organs that are disposed between the liver and the duodenum. Within the liver lobules, there are many fine “bile canals” that receive secretions from the hepatic cells. The canals of neighboring lobules unite to form larger ducts, and these converge to become the “hepatic ducts.” They merge, in turn, to form the “common hepatic duct.” The “common bile duct” is formed by the union of the common hepatic and the cystic ducts. It leads to the duodenum, where its exit is guarded by a sphincter muscle. This sphincter normally remains contracted until the bile is needed, so that bile collects in the common bile duct and backs up to the cystic duct. When this happens, the bile flows into the gallbladder and is stored there.
ERCP is used primarily to diagnose and treat conditions of the bile ducts, including gallstones, inflammatory strictures (scars), leaks (from trauma and surgery), and cancer. ERCP combines the use of x-rays and an endoscope. Through the endoscope, the physician can see the inside of the stomach and duodenum, and inject dyes into the ducts in the biliary tree and pancreas so they can be seen on x-rays.
An ERCP is performed primarily to identify and/or correct a problem in the bile ducts or pancreas. For example, if a gallstone is found during the exam, it can often be removed by means of a treatment instrument, eliminating the need for major surgery. If a blockage in the bile duct causes yellow jaundice or pain, it can be relieved through the use of a treatment instrument inserted through the endoscope.
Since endoscopes are often used to access the tortuous and relatively small cross-sectional areas of a patient's internal anatomical body lumens, repeated manipulation and positioning of an endoscope during a medical procedure can cause problematic side-effects. For example, repeated manipulation and positioning of the endoscope can cause unnecessary trauma to a patient's internal tissues. Improper placement and repeated attempts to access a desired treatment region can exacerbate tissue trauma as well as unnecessarily prolong the medical procedure. Some existing endoscope devices include mechanical positioning components (e.g., elevators) used to manipulate treatment instruments inserted within a working channel of an endoscope. Such positioning devices suffer from imprecise force transmission and slippage between moving components. Accordingly, there is a need for more precise endoscope manipulation as well as manipulating an underlying treatment instrument through an access channel of an endoscope.
Thus, it is desirable to have an endoscope assembly that can more precisely access the tortuous and relatively small cross-sectional areas of certain anatomical body lumens, and more precisely manipulate a treatment device provided within an access channel of an endoscope.